Amphibian aircraft



Cet. 17, 1933. v. J; B'URNELLE AMFHIBIAH AIRCRAFT Filed Nov. 20, 193@ 2 Sheets- Smet 2 UNITED STATES PATENT ol-Fic AMP Amc Vincent J. Burnelli, New York, Y., assigner, by mesne assignments, to Burnelli Aircraft, Ltd., Dover, Del., a corporation of Delaware Application November 2li, lila@ Serial No. 496,34@

5 Claims. (Cl. 24d-2l This inventionrelates to amphibian aircraft through a pontoon, with a wheel and the hyhaving pontoons, and wheels that are extensible draulic raising and lowering means therefor. and retractible with relation thereto, whereby Fig. 6 is a section on the line 6 6 of Fig. 5. the aircraft is rendered operable both upon land Fig. 7- is a section on the line 7-7 of Fig. Il. 5 and water. Fig. 3 is a partial plan view showing the rear e@ One of the objects of my invention is to propart of the pontoon with the tail wheel-skid vide a downwardly open chamber in apontoon in the form oi a rudder, and adapted for the reception of a traction Wheel, Fig. 9 is a partial side view, showing the rear and oppositely disposed guide-ways in said part of a pontoon having a hinged portion carryi@ chamber for a wheel carrier. ing a wheel-skid, and having hydraulic means 35 Another object of my invention is to provide for raising and lowering said hinge portion. a biiurcated wheel carrier whose members strad- In said views let l indicate a fuselage, here die the wheel and provide the journals for the shown as the Burnelli, airfoil contoured type, wheel axle, said members being slidable in the and let 2, 2 indicate pontoons, which are respecl5 guideways and united a cross-piece. tively connected'to the fuselage by struts 3, 3. 0

A further object of my invention is to provide The pontoons are similar in construction, each hydraulic means for raising and lowering the having the bulkheads t and a central well or wheel carrier. chamber 5 produced by an elliptical wall 6 that r-l still further object oi my invention is to is open at the bottom. 7

20 provide wheel braking means mounted upon the The wall 6 has oppositely disposed grooves or 7@ wheel carrier. channels 1 formed therein, as by providing conlviy invention further comprehends an aircavo-convex portions n the sides of said wall, craft having a pair of pontoons, each provided and lining strips 8 are ntted within said chanwith retractible wheels located in a transverse nels, adapted to serve as guide-ways for a vertical plane that lies approximately in the cenwheel-carrying frame. Said trame comprises a s@ tre oi gravity of the aircraft, or slightly in advance pair of spaced vertical. members 9, connected thereof, together with other wheels, journalled near their upper ends by a transverse member in the pontoons, in elevated positions at forl0, and, at their lower ends being connected by ward portions thereof, said forward wheels being an axle ll, upon which a wheel l2 is journalled.

adapted to have surface Contact, in traction of The members 9 of the traine it slidably in the g5 the retractible wheels, c en the supporting airguide-ways e, thereby enabling they trarne with foil of lthe aircraft is e negative angle, and its wheel to be raised and lowered, so that said to be elevated above oriace when the ponwheel can be projected 1oelow the pontoon, for toons are planing on traction purposes, or retracted within the well JL Still another feature or my invention consists when the aircraft is to be used on water.

in the provision oi rear portions or the pon- The transverse member l@ of the trame is protoons, hinged to swing vertically, carrying wheels vided with an upward boss lZa, from which thereI to serve as skids and rear supports, and the extends a rod 13, having a piston le that is reprovision oi hydraulic means for raising and ciprocable in a cylinder l5. Said cylinder, which i0 lowering said rear portions together with the is closed at both ends, as by caps le, 17, is lo- 95 raising and lowering of the traction wheels. cated within a strut 3, and may be secured in a Also my invention includes the feature of the :fixed position in any desirable manner. As pontoon rear portions each carrying a rudder for shown, it is connected by cleats or straps 18 to directional control of the aircraft in Water. brace members i9 that are secured to the strut. i5 Other :features and advantages of my inven- The cylinder 15 is included in an oleo pressure 100 tion will hereinafter appear. or hydraulic system, fluid leads 20, 2l communi-- ln the drawings: eating with the cylinder respectively near its Figure lis a top plan View of an amphibian lower and upper ends for the operation of the aircraft embodying my improvements. piston, to thereby raise and lower the wheel. 50 rig. 2 is a from elevation thereof. 'me fluid reads to, 21 connect with a valve 22 105 Fig. 3 is a side elevation, on a smaller scale, which controls the ow through the leads from of ligs. l and 2. a pump 23, the valve being actuable as by a le- Fig. 4 is a side elevation, partly in section, of ver 2a that is manipulable by the pilot. my improved amphibian aircraft. Since the huid column in cylinder 15 is in- 55 Fig. 5 is an enlarged, partial side section compressible, Il provide an auxiliary piston 25 im within the cylinder, in spaced relation above piston 14, and place a spring 26 between the,

pistons to thereby provide a cushion that becomes effective when the wheel makes contact with the surface in landing, and also aids in absorbing shocks that occur in taxiing over a rough surface.

The transverse member 1Q of the wheel-carrying frame may also serve to carry the brake which is disposed in spaced relation above the wheel. For this purpose lugs 27 depend from member 10, said lugs having pivoted therein a rocker arm 28 that at one end has a slot 29. A brake shoe 39 has two studs 31 that are entered in said slot, and said rocker arm has its other end engaged by a fiexible connector 32 which is extended to the cockpit for operation by the pilot. When the connector is drawn upwardly thereby the rocker arm presses the shoe against the wheel.

A spring, as indicated at 33, may be employed to hold the brake shoe normally retracted.

An inclined piece 34 may be placed just in advance of the well 5, at the base of the pontoon, to serve as a deector and prevent water from entering the well when planing on the surface.

Journalled in each pontoon, within a pocket 35 provided therefor, is a wheel 36, said pocket being located forwardly of the well 5, and near the pontoon nose 37, where the pontoon bottom takes an upward curve. A segment only of the Wheel 36 is exposed below the pontoon bottom, and due to its elevation said wheel is clear above the water surface while the aircraft is planing on water.

The function of wheels 36, as in my co-pending application, Serial No. 265,022, filed March 27, 1928, of which this application is a continuation in part, is to comprise traction means aligned longitudinally with the main traction wheels 12, but lying in a horizontal plane that is above the plane of wheels 12 when the aircraft is in the attitude of normal flight. In consequence, and because the forward wheels obviate the liability of nosing over in making a landing, the supporting airfoils of the aircraft will be at a negative angle when surface contact is made by both pairs of Wheels 12 and 36, whereby air pressure increases the tractive effect of the wheels, and thereby the landing run is shortened. In addition the brakes may be applied unrestrictedly in view of the safety factor of the forward wheels.

Whilst I have stated that the wheels 12 should be disposed about in the centre of gravity of the aircraft, yet if their position be slightly in advance of the centre of gravity as is indicated in Fig. 4, then obviously the aircraft will stand at rest on the surface upon its wheels 12 and 36.

Another feature of my present invention consists in providing a vertical rudder 38 at the stern of each pontoon, said rudders being hinged as at 39 and having a tiller 40 with control connectors 41 that extend to the cockpit. Each rudder also has a wheel 42 journalled therein to serve as a rear skid.

In Fig. 9 there appears a modified form of tail skid for the pontoons, wherein a rear, wheelcarryng portion 43 of a pontoon is hinged as at 44 to the base of the main pontoon portion, and is adapted to be raised vertically when the aircraft is to be used on water. For this purpose the portion 43 has an inclined surface 45 opposed t0 the rear surface 46 of the main portion,

assists the tractive pressure and thereby short- 4 ens the landing run of the aircraft.

This effect in degree can also be achieved when the supporting airfoils under the same landing condition are at zero or even a positive angle of incidence, provided the fuselage is then at a negative angle, and in the instance of the Burnelli type, airfoil fuselage, which itself has a substantial lift over drag character, the sur -face gripping effect produced is quite substantial.

For example, assuming the supporting airfoils A of the aircraft herein illustrated to have a zero or positive angle of incidence when the wheels l2 and 36 are in contact with the surface, and the airfoil fuselage l to at that time have a negative angle of incidence, obviously the lift component of the airfoils A will be at least partially compensated by the downward pressure exerted upon the airfoil fuselage, all in the interest of promoting a better surface grip by the wheels 12 and 36.

Variations within the spirit and scope of my invention are equally comprehended by the foregoing disclosure.

I claim:

1. The combination with an amphibian aircraft having pontoons with retractible wheels, of rear pontoon portions, hinged to swing vertically, skid wheels journalled in said pontoon portions, hydraulic means for retracting said retractible wheels, other hydraulic means for swinging said rear pontoon portions, and control means for the simultaneous operation of both hydraulic means.

2. The combination with an aircraftfhaving a fuselage and pontoons of hollow struts that are positioned intermediate said fuselage and pontoons and constitute connecting means therebetween, said pontoons having Wells therein located about in a vertical plane passing through the centre of gravity of the aircraft, guide-Ways in each well, wheel carrying frames slidable in said guide-Ways, a wheel journalled in each frame, and means that extend into and are secured to said struts, for reciprocating said frames to retract and project the wheels with respect to the pontoons.

3. The combination with an amphibian aircraft having pontoons with retractible wheels, of rear pontoon portions, hinged to swing vertically, skid wheels journalled in said pontoon portions, power means for retracting said retractible wheels, other power means for swinging said rear pontoon portions, and control means for the simultaneous operation of both power means.

4. The combination with an amphibian aircraft having an airfoil fuselage and other supporting airfoils, also having pontoons, of struts connecting said pontoons and fuselage, and bracing means between said pontoons and fuselage, main retractible traction wheels journalled within said pontoons about in a vertical plane retractible traction wheels iournalled within said pontoons about in a vertical plane passing through the centre of gravity of the aircraft, and other wheels -journalled in the pontoons forwardly of the main wheels and positioned above the water line of the pontoons when planing, said airfoil fuselage having a negative /angle of incidence when the wheels all have surface contact.

, VINCENT J. BURNEIH.

I 145VY 

